I wish to add a tikz diagram to one of my questions, but the website doesn't seem to compile. Some help please?
Mathjax doesn't support TikZ, and it would be a very heavy script even if it did. Remember that mathjax is compiled on the client side so putting heavy code in it will just end up in making your answer take a lot of time to load.
Instead, make the diagram in LaTeX (
\documentclass[standalone] is good for this), and upload the image.